CVE-2018-2393 in Internet Graphics Server
Summary
by MITRE
Under certain conditions SAP Internet Graphics Server (IGS) 7.20, 7.20EXT, 7.45, 7.49, 7.53, fails to validate XML External Entity appropriately causing the SAP Internet Graphics Server (IGS) to become unavailable.
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Analysis
by VulDB Data Team • 01/05/2020
The vulnerability identified as CVE-2018-2393 affects SAP Internet Graphics Server versions 7.20, 7.20EXT, 7.45, 7.49, and 7.53, representing a critical XML external entity processing flaw that fundamentally undermines the server's security posture. This issue stems from inadequate validation of XML external entities within the IGS component, creating a pathway for malicious actors to exploit the system's XML parser. The vulnerability manifests when the server processes XML data containing external entity references without proper sanitization, potentially allowing attackers to manipulate the parsing behavior and trigger unintended system responses.
The technical implementation of this vulnerability aligns with CWE-611, which specifically addresses improper restriction of XML external entity reference. When SAP IGS encounters XML input containing external entity declarations, the server fails to properly validate or restrict these references, enabling attackers to craft malicious XML payloads that can cause the server to perform unauthorized operations. This flaw operates at the application layer and specifically targets the XML processing capabilities of the Internet Graphics Server, which is designed to handle and render various graphics formats through web services.
The operational impact of CVE-2018-2393 extends beyond simple denial-of-service conditions, as it can potentially lead to complete system unavailability and service disruption for organizations relying on SAP IGS for their graphics processing needs. Attackers exploiting this vulnerability can cause the server to consume excessive resources, leading to resource exhaustion and system crashes that effectively deny legitimate users access to critical graphics services. The vulnerability's potential for causing widespread service disruption makes it particularly dangerous in enterprise environments where SAP IGS serves as a foundational component for various business-critical applications.
Organizations should implement immediate mitigations including applying the relevant SAP security patches and updates released to address this vulnerability, as well as configuring proper XML parser restrictions to prevent external entity processing. Network segmentation and access controls should be enhanced to limit exposure of the affected SAP IGS instances to untrusted networks. Additionally, implementing comprehensive monitoring solutions to detect anomalous XML processing patterns and establishing robust incident response procedures will help organizations quickly identify and respond to potential exploitation attempts. The ATT&CK framework categorizes this vulnerability under the T1210 technique for exploitation of remote services, making it a primary target for attackers seeking to compromise enterprise SAP environments.
The vulnerability demonstrates the critical importance of proper input validation and the dangers of inadequate XML processing security measures in enterprise applications. Organizations utilizing SAP systems must maintain vigilant patch management processes and conduct regular security assessments to identify and remediate similar vulnerabilities across their SAP landscape. This particular flaw serves as a reminder of how seemingly minor configuration issues in XML processing can result in significant security implications and operational disruptions for enterprise organizations relying on SAP infrastructure for their business operations.